This application is based upon and claims the benefit of priority from the prior Japanese Patent Application No. 11-58752, filed Mar. 5, 1999 and No. 11-94208, filed Mar. 31, 1999; the entire contents of which are incorporated herein by reference.
The present invention relates to a road traffic control system and, more particularly, to a control system for a tollroad having a toll collection system, and a travel time information arithmetic operation apparatus for calculating information associated with the travel time of a vehicle in a specific object section of a specific object route.
Conventionally, information associated with the travel time (time required by a vehicle to travel from a given point to another given point) of a vehicle is obtained from, e.g., space mean speed information obtained from sensors such as vehicle detectors installed on a road.
In use of vehicle detectors, first, a certain object section of an object route is divided into a plurality of unit sections, and a vehicle detector is installed in each unit section. Using a traveling vehicle speed measured by the vehicle detectors, the travel time of the vehicle in each unit section is calculated. The travel time information of the object section of the object route is obtained by, e.g., totalizing the calculated travel times in the unit sections.
In addition, an AVI system has been put into practical use, in which the license plate number of a traveling vehicle is recognized as an image at the two ends of an object section, thereby measuring the actual travel time of each vehicle that has actually traveled in this object section.
With the above method, however, travel time information cannot be obtained in a route having no sensors. Additionally, sensors of certain type cannot obtain usable travel time information unless a number of sensors are densely installed in the route.
As described above, the conventional scheme is capable of obtaining travel time information only in a route having sensors. To apply this scheme to a route having no sensors, a number of sensors must be installed, resulting in high cost.
It is an object of the present invention to provide a travel time information arithmetic operation method and apparatus for calculating travel time
information using data obtained by a toll collection system in a route having no sensors.
According to the present invention, there is provided a travel time information arithmetic operation apparatus comprising a travel time arithmetic operation section which calculates a travel time (time required by a vehicle to travel from a given point to another given point) of a vehicle on the basis of data obtained by a toll collection system installed on a tollroad and representing an entry point, entry time, exit point, exit time, and model of the vehicle, and date, a tollgate data storage section which stores the data obtained by the toll collection system and travel time data obtained by the travel time arithmetic operation section, and a travel time information arithmetic operation section which calculates an average travel time value using the n-minutes accumulated travel time data stored in the tollgate data storage section and generating travel time information.
According to the present invention, the travel time information arithmetic operation section comprises a unusual data removal section which removes, from the accumulated data stored in the tollgate data storage section, unusual data corresponding to data not more than a standard deviation of a travel time data distribution which is defined as a reference, and the travel time average time is calculated using n-minutes accumulated travel time data after unusual data is removed by the unusual data removal section.
According to the present invention, the travel time information arithmetic operation section comprises a necessary data count check section which checks, using data obtained by removing the unusual data by the unusual data removal section, whether data in number necessary for travel time calculation are obtained, a small-number-of-data travel time information arithmetic operation section which calculates travel time information in no traffic jam when the necessary data count check section determines that the data in number necessary for travel time calculation are not present, and a travel time information arithmetic operation section which calculates the average travel time value using the n-minutes accumulated travel time data when the necessary data count check section determines that the data in number necessary for travel time calculation are present.
According to the present invention, the apparatus further comprises an information providing section which provides, to an entry tollgate, travel time information calculated using data collected in units of exit tollgates.
According to the present invention, the apparatus further comprises a tollgate data editing section which rearranges data obtained at exit tollgates in units of entry tollgates, and an information providing section which provides, at the entry tollgate, the travel time information calculated using the data of each entry tollgate, which is obtained by the tollgate data editing section.
According to the present invention, the travel time information arithmetic operation sections are installed in a plurality of continuous routes and obtain a travel time for traveling through the plurality of routes on the basis of travel time information calculated in the respective routes.
According to the present invention, the travel time information arithmetic operation section calculates the travel time information on the basis of data associated with a kind of vehicle using data obtained by deleting data associated with a motorbike.
According to the present invention, there is provided a travel time information arithmetic operation apparatus comprising a travel time arithmetic operation section which calculates a travel time of a predetermined section on the basis of data (data representing the entry tollgate pass time, exit tollgate pass time, model of vehicle, and whether the dates are consecutive) obtained by a toll collection system, a tollgate data storage section which stores the data obtained by the toll collection system and travel time data obtained by the travel time arithmetic operation section, a frequency analysis section which analyzes a frequency of n-minutes accumulated data stored in the tollgate data storage section, a long stopping vehicle data removal section which removes long stopping vehicle data from a result of frequency analysis by the frequency analysis section, an Otsu threshold value arithmetic operation section which using the Otsu threshold method, calculates a threshold value used to divide, into a plurality of divisions, the n-minutes accumulated data after the long stopping vehicle data is removed by the long stopping vehicle data removal section, a cluster analysis section which divides the n-minutes accumulated data into a plurality of data using the threshold value calculated by the Otsu threshold value arithmetic operation section, a unusual data removal section which removes unusual data on the basis of a result from the cluster analysis section, and a travel time information output section which calculates an average value of the travel time on the basis of the n-minutes accumulated data after the unusual data is removed by the unusual data removal section and generating travel time information.
According to the present invention, there is provided a travel time information arithmetic operation apparatus comprising: a travel time arithmetic operation section which calculates, in a tollroad having a toll collection system capable of acquiring data representing an entry point, entry time, or exit time, a travel time required by a vehicle to travel a predetermined section on the basis of data associated with an entry tollgate pass time, exit tollgate pass time, kind of vehicle, and date, which is obtained by the toll collection system; a tollgate data storage section which stores the data obtained by the toll collection system and travel time data obtained by the travel time arithmetic operation section; a first data count check section which checks whether n-minutes accumulated data stored in the tollgate data storage section has reached a necessary data count; a moving average arithmetic operation section which obtains travel time information using a moving average as one travel time information arithmetic operation method when the number of data is small; a free flow travel time information arithmetic operation section which obtains travel time information using a travel time in no traffic jam as one travel time information arithmetic operation method when the number of data is small; an another-section-data-using travel time information arithmetic operation section which obtains travel time information by subtracting data of another section from that of a self-section as one travel time information arithmetic operation method when the number of data is small; a case determination section which when the first data count check section determines that data count does not satisfy the necessary data count, i.e., when the number of data is small, determines, as a travel time information arithmetic operation section to be used, one of the moving average arithmetic operation section, the free flow time information arithmetic operation section, and the another-section-data-using travel time information arithmetic operation section; a frequency analysis section which when the first data count check section determines that the data count is satisfied, analyzes a frequency of the n-minutes accumulated data stored in the tollgate data storage section; a long stopping vehicle data removal section which removes long stopping vehicle data from a result of frequency analysis by the frequency analysis section, a second data count check section which checks the data count after the long stopping vehicle data is removed; an otsu threshold value arithmetic operation section which when the second data count check section determines that the data count satisfies the necessary data count, uses the Otsu threshold method, calculates a threshold value used to divide, into two divisions, the n-minutes accumulated data after the long stopping vehicle data is removed by the long stopping vehicle data removal section; a cluster analysis section which divides the n-minutes accumulated data into two divisions using the threshold value calculated by the Otsu threshold value arithmetic operation section; a unusual data removal section which removes unusual data on the basis of a result from the cluster analysis section; a travel time information arithmetic operation section which calculates an average travel time value as travel time information using the n-minutes accumulated data after the unusual data is removed by the unusual data removal section; and a travel time information providing section which provides the travel time information calculated by the travel time information arithmetic operation section.
Additional objects and advantages of the present invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the present invention. The objects and advantages of the invention may be realized and obtained by means of the instrumentalities and combinations particularly pointed out hereinafter.